This work will continue to define the role of the arginine rich apoprotein on the metabolism of triglyceride rich lipoproteins. It will focus on the mechanism for the plasma addition of the arginine rich apoprotein to these lipoproteins. It will then determine the effect of this addition on the subsequent metabolism of the triglyceride rich lipoprotein with respect to its ability to accept cholesterol esters and its ability to suppress hepatic cholesterogenesis. Further identification of the organic anions associated with native arginine rich apoprotein will be pursued. BIBLIOGRAPHIC REFERENCE: Hepner, G. W. and S. H. Quarfordt, Kinetics of Cholesterol and Bile Acids in patients with Cholesterol Cholelithiasis, Gastroenterology 69:318-325, 1975.